This invention relates to a new and distinct cultivar of Calibrachoa plant, hereinafter referred to by the name xe2x80x98Kakegawa S24xe2x80x99. xe2x80x98Kakegawa S24xe2x80x99 is a new variety of Calibrachoa plant having a creeping, branching habit. The plant grows vigorously and makes an excellent hanging basket. The invention""s flowers are funnel shaped with five-fissured limbs, and a slight indent on each petal. The flowers are single with a diameter of 3.0-3.7 cm when fully open. The petals are pure white with a pale yellow-green corolla throat (RHS 154C). The plant grows and flowers best under low soil pH conditions (pH 5-6). Typically young flowers will close under low light and low temperature conditions such as late in the day or at night.
The genus Petunia was originally established in 1803 by A. L. Jussieu, who described both P. parviflora and P. nyctaginifloa as type species. Using a non-horticultural system that selected the first mentioned species as the type species (lectotype), N. L. Britton and H. A. Brown declared P. parviflora as the type species for Petunia in 1913.
During the 1980""s and 1990, H. J. Wijsman published a series of articles regarding the ancestry of P. hybrida, the Garden Petunia, and the inter-relationship of several species classified as Petunia. These studies revealed that P. hybrida and its ancestral species, P. nyctaginiflora (=P. axillaris) and P. violacea (=P. integrifolia), possessed 14 pairs of chromosomes while several other species, including P. parviflora, possessed 18 pairs of chromosomes. Since P. parviflora was the lectotype species for the Petunia genus, Wijsman and J. H. deJong proposed transferring the 14 chromosome species to the genus Stimoryne. Horticulturists opposed reclassifying the Garden Petunia and in 1986, Wijsman proposed the alternative of making P. nyctaginiflora the lectotype species for Petunia and transferring the 18 chromosome species to another genus. The I.N.G. Committee adopted this proposal. By 1990 Wijsman had transferred several species, including P. parviflora (=C. parviflora) to Calibrachoa, originally established by Llave and Lexarza in 1825. Calibrachoa parviflora (=C. mexicana la Lave and Lexarza) is now the type species for the genus Calibrachoa.
Classification of the current Petunia and Calibrachoa species is still in progress. New species are also being identified. Consequently a proper description has not been written for the Calibrachoa genus. Calibrachoa can, however, be distinguished from Petunia based on the higher chromosome number, chromosome morphology, plant branching habit and type of flower bud estivation. Whereas, Petunia species bear a flower peduncle and one new stem from a node, Calibrachoa bear a flower peduncle and three stems. Petunia species have a cochlear corolla bud, a single outermost petal covers the other four, radially folded and terminally contorted petals. Calibrachoa flower buds are flat with all five petals linearly folded and the two lower petals forming a cover around the three other petals and fused together.
Asexual reproduction of xe2x80x98Kakegawa S24xe2x80x99 Calibrachoa originated from a hybridization made in 1996 by the Sakata Seed Corporation, Kakegawa breeding station in Kakegawa, Japan. The female parent was a deep rose (red-pink) petaled, decumbent habit plant known as xe2x80x98Liricashower Rosexe2x80x99, a plant described and illustrated in U.S. Plant Pat. No. 9,884. The male parent was a white flowered, decumbent habit breeding line known only as xe2x80x98White #1xe2x80x99. The initial cross-pollination of the parents resulting in F1 generation seed, was made in October, 1996. In February, 1997, the F1 seed was sown and yielded 15 plants. From these 15 plants, three plants were selected for appealing flower color and creeping, branching plant habit. That summer the three selected plant lines were intercrossed to produce F2 seed.
In February, 1998 the second generation seed was planted in the field at Kakegawa, Japan. Five plants were selected from the F2 generation for their white flower color and creeping, branching plant habit. These five plants were asexually reproduced and tested for easy reproducibility and stability of traits. In 1999 three of these lines were selected and propagated again for evaluation. Trait stability was confirmed in all three lines in greenhouses in Japan.
Also in 1999, cuttings of this plant line were sent California. During this Summer plants were grown under the direction and supervision of the inventor for evaluation of stability of the line""s desired traits. Plants were evaluated in hanging pots at the research station in Salinas, Calif. Final selection of one line as the new variety was made in California. The present invention, xe2x80x98Kakegawa S24xe2x80x99 Calibrachoa was determined by the inventor to have it""s characteristics, as herein described, firmly fixed.
The plant was asexually produced by excising the terminal 1.0 to 1.5 inches of an actively growing stem. The basal half is stripped of leaves and dipped in a 1:19 dilution of Dip-N-Gro(trademark) rooting solution (solution: water). Plastic cell trays with a 1.0 inch diameter by 1.5 inch deep cells are filled with a peat-moss based growing media. The basal portion of the stem is then inserted into moistened peat-moss media. The cuttings are kept in a warm greenhouse under a clear plastic tent with occasional misting from an automatic watering system. The cuttings are fully rooted in six weeks.